Background: Annually 15 million people worldwide suffer from a stroke. Different rehabilitative approaches are used for post-stroke treatment. One of them is Motor Imagery (MI). MI allows patients to mentally practice a task, which they cannot yet carry out physically due to motor impairment. MI was initially developed to improve the performance of athletes and has been adopted in rehabilitation programs for persons with stroke to support motor recovery.

Objectives: To conduct a systematic review of the literature on how Motor Imagery and conventional therapy (physiotherapy or occupational therapy) compare to conventional therapy only in their effects on clinically relevant outcomes during rehabilitation of persons with stroke.

Search strategy: The authors searched the following databases for relevant studies: Ovid MEDLINE (Ovid version, from inception to August 2005), PEDRO (online version, University of Sydney, Australia, August 2005), PsycINFO (from 1967 to July 2005), Psyndexplus (from 1977 to June 2005), CINAHL (Cumulative Index to Nursing & Allied Health Literature, from 1982 to July 2005), Cochrane Central Register of Controlled Trials (Oxford, UK, 2004, issue 1), and Scopus (from inception to August 2005). The search was conducted without restrictions to language

Selection criteria: The authors included all randomized controlled trials that compared conventional physiotherapy or occupational therapy to MI combined with conventional physiotherapy or occupational therapy in post-stroke rehabilitation. Studies were excluded that focused on mental practice based on computer-animated techniques, because these techniques are not available in most rehabilitation settings. Only studies about patients with a first episode of stroke were considered with no restrictions concerning age or time since onset of stroke. The outcome assessment had to be clinically and functionally relevant, for example performance of specific tasks and activities or health-related quality of life.

Data collection and analysis: Two reviewers screened the titles and the abstracts of all references (N = 2116) independently. The reviewers independently recorded details about study design, interventions, outcome measurement methods, and results in a predefined form. Both reviewers separately evaluated the quality of the included trials based on a detailed list of quality items.

Results: The authors identified four randomized controlled trials from Asia and North America. The quality of the included studies was poor to moderate. Two different Motor imagery techniques were used (three studies used audiotapes and one study had occupational therapists apply the intervention). Two studies found significant effects of Motor Imagery in the Fugl-Meyer Stroke Assessment and in the Action Research Arm Test. One study did not find a significant effect in the Fugl-Meyer Stroke Assessment and Color trail Test but in the task-related outcomes.

Conclusion: Current evidence suggests that Motor imagery provides additional benefits to conventional physiotherapy or occupational therapy. However, larger and methodologically sounder studies should be conducted to assess the benefits of Motor imagery.